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Vindi submitted a New Scientist story about a CPU fan that flaps in the breeze. 2cm metal or polyester
fan blades, and use less power then a traditional rotary fan. They move less
air then the traditional fan, but for laptops, using 99% less power
can't hurt. Update Hey its a duplicate from saturday! Guess I shouldn't
post while planning my trek to see LotR tomorrow. Go ahead, flame on.

I've been looking into this a lot recently, and there's some pretty (ahem) cool developments on the cpu front recently, with x86 architectures.

Some people point to the VIA C3-800, but if you have real computing needs, steer clear. It runs comparable to a Celeron 400, which is almost, but not quite adequate for general computing. Instead, check out the old reliable suppliers. The shift to.13u means a lot. Frequencies are so high and chips are so powerful that underclocking has become a real option. A good general target for fanless operation is about 12 watts. You can go higher with good case airflow, or lower if you're dealing with troublesome ambient temperatures.

Right now, you can take the Intel Tualatin pIII 1.13GHz (28W), cut the bus speed to around 100MHz, cut the voltage down to about 1.1v and be right in the target range. Of course you won't know exactly w/o experimentation on your cpu, but it *should* be doable. If you're worried about losing efficiency to bus speed, remember that you can compensate by running it on one of the PIII DDR chipsets that are now available (upping effective bus speeds to 200MHz) or waiting until February, when Intel says they'll release a similar part themselves. Additionally, the 512k (vs 256k) cache on the pIII-s will offset lower bus speeds. Just check out the specs of the PIII-M LV models at developer.intel.com and ask how they got to those low wattage numbers with the same core. Since the last fanless G4 was 400MHz and claimed (in its wildest fantasies) to be a supercomputer twice as fast as a pIII, a fanless 800MHz pIII is not insignificant.

Even better, surprise, is AMD. The current mobile palomino runs at 1.1GHz, 1.1v, 25w. This is clearly just an underclock of the current 1.75v desktop XPs. But what it tells you is that the AMD architecture is very open to undervoltage at lower clock speeds.

Now if you consider AMD's forthcoming die shrink, things really look good. Zdnet.de reported (unsourced) that the Athlon 1.73GHz processor would drop from about 75W to 45W after the changeover. Depending on how far you could drop the voltage, you could be looking at a 1-1.2GHz part running at about 10W! Fanless! Now imagine (a beo..no) 2 of these in a well ventilated case, with an MPX board -- 2GHz of dead silent AMD power! Wooo!

At first it would seem like a good idea, but of all my friends whom I've convinced to buy 1.4 gig thunderbirds, they've all complained of the noise, but none of them are willing to underclock. They argue that if they paid for a 1.4 gig, they're going to run at 1.4 gig. Hard to convince people to pay a $100+ premium for a top of the line chip only to run it at a mediocre speed when the only consequence is a little bit of noise.

It depends on your priorities. If you are an audiophile something like this might be advantagous if you didn't have the $$ for a soundproofed case. If I wasn't such a speed hound I'd like to do something about that, because the white noise prevents me from hearing the true sound of my music on my PC.

I've been looking for a good Internet Appliance [yafla.com] and a CPU that runs at a low enough temperature to require just a passive heatsink (no fan) is something I'm really looking for. Any suggestions?

The problem is the "oomph" required to do MPEG2 decoding -- this usually dictates a CPU with enough horsepower to need active cooling. However, if you look at the RealMagic Netstream 2000 by Sigma Designs [sigmadesigns.com], you'll find a PCI MP@ML MPEG2 TS and ES decoder card that does not require active cooling and works with a lowly P133.

One can imagine a settop box based on this combination that would fit the bill. It gets better... there is such a beast, and it runs on Linux: The VIP30306n [gctglobal.com]. This little puppy uses the Sigma Designs em8400 MPEG2 chip... the same one as in the RealMagic Netstream2000.

The downside is price: the Netstream2000 runs around US$220, and I'd expect that the GCT Allwell box would be US$500 or so.

It comes with mobo, and power supply, on board ether, s3 savage4 agp (even tv out), audio (only 2 channel), usb, firewire, plus one pci slot. I personally put a wintv card in it so I can use it as a tv, and a dvd drive to play dvd, but you could easily put in a dolby 5.1 card instead of the wintv card.

I put a 1 ghz celery in it, but as it stands it's rather noisy, casefan + cpu fan + psu fan + hd. But if you get a via c3 [google.com] it should be able to run without a cpu fan.

It also should be possible to also hack out the small, noisy case fan that it has now and put in larger, and quieter case fan. Dremmel tool is probably required for this one, or a very nimble hand with tin snips.:)

Another thing you might to do quiet it up a bit is search for silent drives, I think seagate either makes or is going to make a quiet ide drive. There's also sleaves you can get for ide drives to quiet them, but that might require your only 5.25 bay, which means you'd then need a usb or firewire dvd drive.

Mine's more of a do it yourselfer but it has pretty much standard hardware, and should have enough horsepower to do pretty much anything that you'd want to do with it, sans FPS games, because of the slow 3d video. 2d is fine though.

sv24=$250 via c3~$70? hd=$100-150, dvd drive=$60? You pretty much have a machine after that, and any thing else is optional.

Yeah, I looked at that. The noise and form factor turned me off. It's kind of tight in there, airflow-wise, but you're right about using a Via C3 to mitigate the CPU fan requirement. If the case fan was quiet, it would be much more desirable.

As for disk drives, I think we had a diskless client set top box in mind, with content streamed from a server elsewhere.

The GCT Allwell VIP3030n is really nice, though the processor may be a bit underpowered for rendering comples web pages as it uses an NS Geode. Still, for a/v streaming, it's probably fine.

It's definitely pretty tight, though hacking in your own case fan might solve the airflow problem. I'm not a big fan of case modding, but I believe I might have to make the new case fan my first attempt.:)

The psu fan is still pretty darn noisy though, with the size of the psu, there's no way that's going to be easily replaced.

The big thing about the via c3 is that supposedly the 866's and 933's are out, but I can't find them anywhere for sale. They have a slow fpu (runs at half clock), but that doesn't seem to hurt real world applications that that much suprisingly enough. I'll probably have to try one of those down the road.:)

I love the form factor of that unit (at the very least it's a lot easier to put in a hidden location where the sound will naturally be dampened somewhat), and I didn't even know about the VIA C3 before so that is a fantastic bit of knowledge for refining the search (the C3 does seem to be key to a reasonable performance IA type system). I don't need DVD or floppy drive performance though, apart from during installation, as I want media to come over the home network.

Yeah, it's cute little machine.:) I just found out about the via c3 myself, it's a promising lower power, low noise chip, I wish more people would push chips in that direction, as I'm around computers enough that I'm starting to despise how noisy they are, especially if you want to play music where the dynamics actually matter.:) I recently put a zalman flower [overclockers.com] in my 1.33ghz Athlon box and now the worst thing is that the hard drives make too much noise now!

It's a definite improvement over the Aluminum tornado that I had in the box before, it even runs 6 deg C cooler now.

I have a p233 and the local computer shows have some nice quiet cpu fans for the p233. The power supply fan also went(couldnt figure out why the machine was so quiet:-) ) so I replaced the fan and the new ball bearing fan was the noisest thing I ever heard. So I went to radio shit and got a 82 ohm.5 watt resistor and hooked it up in series and it is now very quiet. I tried 100 ohm but the fan wouldnt startup. I use this machine as the house linux server and it stays up 24/7 and of course it ends up in the bedroom:-)

No fan in any of the slot-loading models, all the media playback you can want, etc. Yes, the cheapest new model is $799, but none of the "slot-load" iMacs have a fan, and can be found fairly inexpensively on eBay.

And if the thought of running the MacOS bothers you, you can run Darwin and X Windows, and still use the Firewire and Airport connections. Just pretend it's BSD but in a differently colored box.

Well I most certainly have nothing against Macs, or the MacOS: Again I'm looking for something as a Internet Appliance and if it performs the desired task then I'm very happy indeed. However the iMac doesn't fit my needs because of the CRT screen (which greatly increases power consumption, heat generation, and of course makes it much bulkier). Also the MacOS isn't an instant on type system. Otherwise I think the Apple products are fantastic.

However, they're not cheap. Pricing starts at $149. Additionally there is a Piezoelectric Resonant Blade Element [piezo.com]. Interesting stuff. Hopefully mass production of piezoelectric fans will lower their price to the average customer range.

2 cfm ? You couldn't even cool your own self with that kind of non-power. Most mid-range CPU fans move 30-35 cfm, top-end case fans move 130+ cfm. You'd need a beowulf cluster of piezo fans to get that Athlon to just Post.

Hrm... in that case, it would be removing the heat from the CPU (by turning it into some other form of energy). So the end result would be a dynamic heatsink (as opposed to a static one without moving parts) that cooled more efficiently as it got hotter, because it would move air through itself.

You could do something like this simply by adding a fan to the top (it would work like those Christmas candle things at craft fairs, the rising hot air would turn the fan), but I doubt this would generate enough air flow to make it worthwhile.

My guess would be that if there was a simple way to turn this heat into enough electricity to power a fan to cool off the heat (which would in turn shut the fan off by reducing the voltage), someone would have done it. Either that, or I should go apply for a patent.;)

Hrm... in that case, it would be removing the heat from the CPU (by turning it into some other form of energy). So the end result would be a dynamic heatsink (as opposed to a static one without moving parts) that cooled more efficiently as it got hotter, because it would move air through itself.

Unfortunately, it would have to have some sort of capacitor to smooth out the power source, or it would only work in spurts - if it worked too well the CPU would become cool for a short time, cutting off power to the "dynamic heatsink". Unless this device were very quiet, I imagine the clicking noise from turning itself on and off (or merely revving up and down) would get annoying. Not to mention probably wearing out the part.

The other difficulty is, of course, in designing something that converts heat into a usable form of energy with temperature differences less than, say, what you need for a steam turbine. No present solution to this problem seems to be particularly cheap.

As long as there is also a colder region (e.g. the case) it is theoretically possible; bimetallic rods connecting the two sources can induce a current for example.
Unfortunately, the current generated would be very small (no, I have no figures/equations to back this up) It may seem as though the heat difference would be large, as we've all seen the THG video, however bear in mind the purpose would be to keep the chip at ~30C. So that's only a ~10C difference in temperature - not really going to be enough energy there to power a fan, and the efficiency of the process would be so low that it's hardly a super-efficient heat-sink either.

...somehow use the heat from the CPU to power the fan. As the CPU got hotter, the fan would move faster.
I have no idea how this could be done, but there must be a way.
There sure is. Have you seen the lights in the stores that have the shade that rotates as long as the light is on? Same thing. The convection action of the heat from the light spins the fan. Same thing with what you propose-- the convection from the processor would spin the fan. More importantly, having the fan in the way will slow the airflow around the processor, thus meaning that the processor gets warmer. The microcurrent from the fan spinning would not end up generating enough power to be worth it, either.
Ultimately, in my opinion, there would be a large copper (better yet, silver) block that extends from the processor to the face of the computer itself, with a huge aluminum heat sink on the case. (Copper has a very high coefficient of thermal conduction, silver is better yet, but expensive. Aluminum isn't that great, but aluminum oxide is far better than copper oxide or silver oxide, so it's a great medium for heat exchange with the air.)

i wonder how hard it would be for them to recycle an entire computer's heat back into energy.. that would certainly make laptops run forever and a half....

An entire computer's heat? Not possible, thanks to thermodynamics - you're talking perpetual motion here. And, since heat has so much more entropy than electricity, you probably can't even come close, even theoretically.

And don't forget the light output from the laptop's LCD, or the other EM output from the various motherboard components. The only way to "recoup" some of that power would be to harness the kinetic energy wasted on moving the keyboard keys track ball.

Easier by far to keep coming up with ways to (a) use less power and/or (b) store more power.

The problem is that putting a thermoelectric generator (or any other sort of heat-driven generator) in the heat path from the CPU increases the thermal resistance, so the CPU core gets hotter...

Of course, heat makes air move directly. Design your heat-sink and case to take advantage of that, and you shouldn't need a fan unless the cooling requirements are outrageous. Problems are:
--The user can't lay the case on it's side or otherwise change the orientation from what the designer intended.
--The case, mobo, and heat-sink have to be designed together, and the user can't add anything inside the case, as it might change the airflow.
--Most CPU's cooling requirements _are_ outrageous if run at full rated speed.

So I wouldn't want a box designed for natural convection only. But for the user that finds adding a USB peripheral challenging, doesn't need 1GHz, and doesn't want that fan humming, maybe it would work.

So I wouldn't want a box designed for natural convection only. But for the user that finds adding a USB peripheral challenging, doesn't need 1GHz, and doesn't want that fan humming, maybe it would work.

It's been done, by apple (who else?). Since the introduction of the models that had slot-loading CD drives in October 1999, iMacs have been fanless, cooled totally by convection currents. Not surprisingly, the iMac was designed for the novice user who doesn't need 1GHz and won't ever be dinking around in the thing's innards, so convection cooling was the way to go.

The G4 Cube was also cooled in this manner, but that model was directed at studio managers and CEO types who likewise wouldn't need expandability.

It's been a while since I pondered the intricacies of slashcode, but they could probably filter it so that it caught TLAs which were uppercased (well, any three-letter word which was uppercased, it wouldn't know it was an acronym). This would catch stuff like IBM and CSS, since those are the kinds of things people would like to be able to search on.

I had a peizo fan in my old Mac (a 128 with a Levco MonsterMac 2 meg upgrade) back in 1986. It had two strips (about 1cm by 4cm) sticking out of the top, and the strips vibrated. It was held in there by velcro and just pushed the air around. (It did not attach to a CPU or anything like that.)

It's kind of hard to tell exactly what this article is describing, but it sounds like exactly the same thing at half the size.

Yes, peizo fans have been around a long time. They use a crystal which shrinks or expands when in an electric field. So you attach levers to the crystal so a small dimensional change flaps the wings, and put in a little inverter circuit to apply AC to electrodes on the crystal.

I don't know if there is any real advantage to this as compared to regular motor-driven fans. It takes a certain amount of power to move a certain amount of air, and AFAIK electric motors are pretty efficient. I don't know the efficiency of piezo devices, but I don't see how it can get much more than electric motors -- if a piezo fan takes 0.01 times the power, it's probably moving 0.01 times as much air, and that's not going to keep your 2GHz CPU cool. But if you actually want that tiny of a fan, I expect piezo will scale down easier than motors.

Also, most small fan failures are due to the bearing going out. Piezo devices don't have to have bearings -- you can just bend the wings to flap them instead. If you can find material that will bend back and forth forever without failing, peizo might be more reliable. But that's a big "if".

For those who are unaware, piezoelectric crystals are items that will change shape under the application of an electric field and/or generate a potential difference (i.e. a voltage) when squeezed.
They're used in inkjet printers - they're in ink some cartridge when an electric field is applied to them and they change shape, forcing the ink out of the I also hear the they used them in the ipod for some sort of playlist control mechanism.

...they used them in the ipod for some sort of playlist control mechanism.

The only place the iPod would have a piezoelectric element would be for its speaker. The iPod makes audible clicks when you navigate its GUI. Just one of the many small details that makes the iPod supercool.

Why isn't there a moderation system set up for the stories that are posted? What I mean is the stories themselves should be modded just like the comments. I think that would make the most open system possible. Also, the editors would have an additional measure to the types of stories that people respond to. That way things like this would be modded down as a repeat and ignored much easier.

How can this possibly be offtopic? Right in the story its talks about it being a repeat. Why don't you friggin' moderators tell me what the appropriate forum would be for this type of comment? I'm sick of getting modded down for stupid shit....well anyway end of rant. I probably just blew more karma, oh well.

This is just an excuse for designers to make CPU's less efficent and more power hungry.

Imagine...

Washington Post: Dec 13, 2018. Details are now emerging about the accident that irradiated much of Germany on Tuesday. Nothing is as yet confirmed, however, initial reports indicate that a heatsink was somehow removed from an AMD processor (PR rating 10,000,000). A bizzare terrorist group with the initials THG may have been involved. Containment was lost, and critical mass was reached almost immediately. AMD representatives have issued a statement in the wake of the carnage: "Obviously, they were using an improperly designed motherboard."

Flame #1: Why is Overrated/Underrated not M2'd? The conspiracy theory here is that since editors moderated with unlimited points [slashdot.org], its a way for editors to moderate things they don't like (censorware, anything said badly about them) down without feeling the wrath of M2!

Flame #2: Is the AC privacy on slashdot really safe [slashdot.org] after upgrading to Slash2.2??

Flame #3: Do you really think that people with a lot of comments need to get out more [slashdot.org] even though they are indirectly lining your wallet?

Let the flame war begin!
And remember moderators, this is on topic, cause Taco said to "Flame On!" (at least gimmie a point for attempt at humor):-P

Okay... I'll flame away. The constant, repeated posting of duplicate stories, often within a day or so of each other demonstrates an unbelievably poor level of editorial oversight. I propose that/. editors lose editorial privilages for 24 hours after each such obvious gaff.